Means for locking incandescent-light bulbs.



No. 740,248. PATENTBD SEPT. 29, 1903.

' c.- w. DARE a: c. B. MAGDUFPEEL MEANS FOR LOOKING INGANDBSOENT LIGHT BULBS.

APPLIGAIIQH'IILED FEB. 18, 1903.,

F0 MODEL.

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' AYTOHNEY UNITED STATES CHARLES w. nAnnANn CHESTER E Patented September 29, 1903.

i P TENT OFFICE.

. MAODUFFEE, OF NEW YORK, N. Y.

SPECIFICATION formingpart of Letters Patent No. 740,248, dated September 29, 1903.

I Application filed February 19, 1903. Serial No. 144.040. (No model.) 1

To aZZ whom it may concern:

Be it known that we, CHARLES W. DABB and CHEsTEn E. MAGDUEFEE, citizens of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Means for Looking Incandescent-Light Bulbs, of which the following is a full, clear, and exact specification.

This invention relates'to means for locking incandescent-light bulbs in the sockets, so as to prevent unauthorized removal either for the purpose of substituting lights of a greater power or for the purpose of carrying the bulbs away entirely.

In hotels particularly great trouble is caused and much additional expense entailed by the carrying away of small portable articles of furnishing. Extra expense in the cost of lighting has been entailed by the substitution of a light of agreater candle-power for the ordinary light.

As ordinarily constructed incandescentlight bulbs are either screwed into a threaded socket or are attached to the socket by a bay onet-joint. This permits them to be easily removed and carried away.

Our invention has forits object the attachment of the bulbs to the sockets in such a manner that they cannot be removed without breakage by unauthorizedpersons. In order to remove bulbs provided with our invention, special appliances will be necessary which the ordinary guest at the hotel does not have. We have shown two ways of locking bulbs in their sockets-one by means of a screw which is turned by a special key and the other by means of a padlock which must be opened by a special key.

We will now more particularly describe our invention, reference being had to the accompanying drawings, in which Figure l is a partial cross-section showing our invention applied to a screw-threaded lamp-socket. Fig. 2 on the line 2 2 of Fig. 1 shows the bulb located in position. Fig. 3 shows a threaded bulb having the'lockinggroove in the ferrule instead of being blown in the glass, as in Fig. 1., Fig. 4 represents a modified construction, wherein we use a split ring, which is fastened together by a padlock.

Numeral 1 represents an ordinary incandescent-light bulb, and 2 its socket. In the upper part of the bulb, near theneck, we form a groove 3. To the lower end of the socket we attach a lug i, which is internally screw threaded and has a locking-screw 5, having an irregularly-shaped head 6, which is adapted to be engaged by the key 7. It will be ob vious that. the bulb will be fastened .in the socket when'the screw 5 is in engagement with the groove 3, thereby preventing the bulb from being removed unless by breakage or by withdrawing the screw. The key is removable and is intended to be used only by persons authorized to attend to the lights.

In Fig. 8 we have shown the groove 3 in the lower end of the ferrule 8, which is generally fastened to the bulb by means of plaster-ofparis. In other respects the operation is the same as in Fig. 1, where the groove is blown into the glass. In Fig. 4 we have shown a modified locking mechanism comprising two semicircular rings 9, having the inturned ends or books 10 and eyes 11. In this form the socket merely has a hole through it in such a place that it will register with the groove in the bulb. The hooks 10 are inserted through the hole in the socket and then the eyes are brought together and locked by the padlock. W'Ve do not desire to be limited to the precise construction we have shown, her is it essentialthat the lockin g device be located at the lower end of the lamp-socket, as it might be equally effective if located at such a place as to register with a groove in any other portion of the bulb. We also do not desire to be limited to any specific locking device, as many ways of securing our object will occur to a skilled mechanic.

What we claim as new, and desire to secure by Letters Patent, is-

l. A locking device for lamp-bulbs, comprising a socket having a hole therein, a bulb having a groove adapted to register with said hole, a pin adapted to project through said hole into said groove and means for locking said pin to said socket, substantially as described. I

2. A locking device for lamp-bulbs, comprising asocket having a hole therein, a bulb having a groove adapted to register with said hole and a locking device passing through said hole from the outside and adapted to project into said groove, said locking device having a groove adapted to register with said being incapable of removal without special hole, alocking-ring havinga projection adaptappliances, substantially as described. ed to project through said hole into said 15 3. A locking device for lamp-bulbs, corngroove, and means for locking said ring to 5 prising a socket having a hole therein, a bulb said socket, substantially as described. having a groove adapted to register with said In testimony whereof we aflix our signahole, a split ring comprising two portions tures in presence of two witnesses.

each having an inwardly-projecting end and CHARLES W. DABB. an eye, and a lock for binding the bulb, socket CHESTER E. MAODUFFEE. i0 and ring together, substantially as described. Witnesses:

4. A locking device for lamp-bulbs, com- JACOB H. SHAFFER,

prising a socket having a hole therein, a bulb i JULIAN S. WOOSTER. 

